At present, the most common way for bitcoin mining is miners joining in a pool. However, there is a phenomenon that the mining pools penetrate each other, which will result in a decrease in the miners' income of the attacked pools, and a reduction in computing power of the attacking pools. Therefore, the overall computing power of the bitcoin system is reduced. Aiming at the problem of mutual attack and non-cooperative mining between mining pools, an Adaptive Zero-Determinant strategy (AZD) was proposed to promote the cooperation of miners. The strategy adopted the idea of comparing expected payoff with cooperation and defection in the next round then choosing a strategy with high payoff. Firstly, miners' payoff in the next round under two situations could be predicted by the combination of Temporal Difference Learning Method (TD(λ)) and Zero-Determinant strategy (ZD). Secondly, by comparing the cooperation payoff with defection payoff in the next round, a more favorable strategy was chosen for miners by Decision Making Process (DMP), so the cooperation probability and defection probability in the next round were changed correspondingly. Finally, through the iterative implementation of AZD strategy, the ming pools in the network would cooperate with each other and mine actively. Simulation results show that compared with adaptive strategy, AZD strategy increases the speed of converging cooperation probability to 1 by 36.54%, compared with ZD strategy, it improves the stability by 50%. This result indicates that AZD strategy can effectively promote the cooperation of miners, improve the convergence rate of cooperation and ensure the stable income of mining pools.

Concerning the ranging inaccuracy problem based on radio signal phase information under multi-path environments, a two-step ranging approach based on double tags was proposed. Each target was attached with double tags. Through single frequency subcarrier amplitude modulation, firstly, the wrapped phase information of carrier signal was extracted, the distance between reader and tag within half wavelength of carrier signal was calculated and fine ranging estimation value was achieved. Secondly, the unwrapped phase information of subcarrier signal was extracted, and the integral multiple of half wavelength within the distance of reader and tag was calculated. Thirdly, the average multiple was calculated between double tags, the distance of average multiple of half wavelength was used as coarse ranging value. Finally, the final ranging result was estimated by the sum of the fine ranging value and coarse ranging value. Additionally, single reader and double-tag based geometric localization method was introduced to reduce the cost of hardware facilities. The simulation results show that, under multi-path environments, compared with the directly ranging with subcarrier phase, the average ranging error of double tags based two-step ranging approach is reduced by 35%, and the final average localization error is about 0.43 m, and the maximum error is about 1 m. The proposed approach can effectively improve the accuracy of phase based localization technology and also reduce the hardware cost.

The boundary identification of punctuation marks is an important research field of natural language processing. It is the basis of the application of word segmentation and phrase chunking. In order to solve the problem that the boundary identification of Chinese slight-pause marks which split the coordinate words and phrases in Chinese, the Conditional Random Field (CRF) that used for sequence segmentation and labeling was adopted for slight-pause marks boundary identification. At first, the slight-puase marks boundary recognition task was described in two types, and then the slight-puase marks corpus tagging method and process and feature selection were studied. According to the methods of corpus recommendation and ten-fold cross validation, a series of experiments were carried out in slight-pause marks. The experimental result shows that the proposed method plays an effective role in slight-pause marks boundary identification with selected boundary identification features. And F-measure of boundary identification increased by 10.57% on baseline as well as the F-measure of words divided by slight-pause marks achieves 85.24%.

Concerning the problem that typical time synchronous algorithms used in multi-hop Wireless Sensor Network (WSN) mainly focus on increasing the network synchronization precision, but ignore such issues as the network energy, path hop and error accumulation, a cluster-based and energy-efficient hierarchical time synchronization algorithm was proposed based on a cluster hierarchical network structure. In this algorithm, a cluster node was selected to take a two-way synchronization with the cluster head, and its neighbor nodes achieved bidirectional synchronization indirectly through the passive monitoring mode. In such a way, the number of the packet's transmission was reduced while the digital signature pattern ensured the safety of transmission. In addition, the cycle update coefficient of synchronous group delay was quoted to further reduce the consumption of synchronization packets. The simulation results show that the algorithm reduces the energy consumption and prolongs the network life time, therefore this algorithm has certain practicability.

In order to improve the security and flexibility of digital image information hiding, adopting the theory of sub-affine transformation, a new image encryption algorithm based on three dimensional sub-affine transformation was designed. By analyzing the constraints of three dimensional sub-affine transformation, according to the relation between variables and randomness of variables, a rapid construction method of three dimensional sub-affine transformation was given. Three color components of each pixel in the color space chose different ways to transform for achieving image scrambling, and its periodicity was discussed, for proposing the concept of singularity point and fake period. The experimental analysis shows that the algorithm has good effect of scrambling, larger key space, flexible encryption, and high security. And its diffusion and disturbance are ideal.

The solutions for porting programs from single-address space operating system to multiple-address space operating system were illustrated and contrasted in the architecture of embedded MIPS. Then a solution named "single device, multiple modules and architecture porting" was introduced to the program porting from Nucleus to Linux. Experiment results show that this solution is executable, low costing and effective.

Low expandability and overweight of telecom backbone in mainstream P2P network model have been hampering the development of P2P system. Though structured overlay network model solves part of problems, it is difficult to be applied into Internet due to its limitations. By analyzing other P2P models, this paper provided a hybrid model based P2P network model, and described some important processes in the model. A manager protocol and new key matching algorithm were also proposed to enhance the management and practicability of P2P network.